This invention is a modification of the invention described in co-pending application Ser. No. 468,404 filed May 9, 1974, now issued as U.S. Pat. No. 3,924,100 dated Dec. 2, 1975 and assigned to the assignee of the present application. It relates to the delivery of prepared meals to locations remote from the point of preparation and more particularly comprises a new concept in the feeding of patients in hospitals, nursing homes and other institutions, the feeding of hotel guests in their rooms etc. In the following description the invention is described in terms of its use in a hospital but it is to be borne in mind that the invention has wider applications.
Hospitals use a variety of different systems for serving meals to their patients. These systems generally fall into two categories, frequently identified as centralized and decentralized methods. And the systems in each category include a variety of different techniques intended to bring food to the individual patients at the desired temperature.
In the centralized methods, the food is prepared in a main kitchen where the entire meal is set up on individual patient's trays, and the trays are transported directly to the patients. The heated pellet system, hot and cold cart system, and insulated nestable tray-thermal column system, all used in an effort to maintain the food at the desired temperature are categorized in the centralized system of food distribution.
The decentralized method generally includes two alternative heat systems, namely, conventional and microwave systems. In conventional decentralized systems, the food is prepared in central kitchens and transported in bulk to floor pantries on the different hospital floors where the patients' trays are set up. In the microwave system, the prepared food is either kept in a freezer or refrigerator, and just prior to serving, the food is allowed to thaw and is then heated in a microwave oven in the floor pantry. Thereafter it is promptly delivered to the patient.
All of the various centralized and decentralized systems have disadvantages. For example, the pellet systems employ a metal disc preheated to 250.degree. -450.degree. F. as the heat source in the tray to maintain hot food at the desired temperature, and the pellets constitute a hazard to the patient and kitchen personnel. If the pellets are overheated, they cause the foods to overcook or dry out. The effective temperature retention time is limited to approximately 45 minutes. And the pellets are heavy, adding substantial weight to trays. In hot and cold cart systems, wherein the carts for the trays have separate hot and cold sections, there is a tendency to overcook and dry out the foods in the hot section, and cold and hot foods must be combined on the trays before service. Utility outlets are needed in both the kitchen and on the patients' floors, and the carts normally are on current for 7 or 8 hours daily. And they do not generate heat in transit. The carts are difficult to clean and require substantial maintenance, and the carts are costly, heavy and have limited tray capacity. In insulated traythermal column systems wherein the trays nest on top of one another so that all the hot foods stack on top of each other and similarly all the cold foods stack on top of one another to form thermal columns, the trays are bulky, heat is conducted in the tray skins from the hot to the cold columns, and the systems have a limited temperature retention time. Furthermore, without lids on the separate trays, the tray bottoms become soiled from the food in the next lower trays in the stack.
In the decentralized systems, labor costs are relatively high as more people are required to operate the systems, food costs are higher because of waste and unauthorized consumption, food odors are created on separate floors because of the floor pantries, and dish handling noise is created on the floors when china is used.